1. Field of the Invention
The present invention is directed to the display of manually entered, computer generated or measured data on a multi-parameter aircraft instrument display, such as a flat panel display, in which there are a plurality of simultaneously displayed parameters, and more particularly to a method and system of providing easily recognizable visual confirmation to the user that the correct parameter in the multi-parameter display is being manually varied or has fallen within a certain range from a particular value, such as a target value.
2. Description of the Related Art
In the operation of an aircraft it is commonly necessary or desirable to manually or automatically set or adjust, and in some cases to periodically reset or readjust, a variety of course, instrument and environmental settings and parameters that are utilized in flight and ground operations. For example, the local barometric pressure may be set—initially using the local pressure measured at the airport when the aircraft is on the ground prior to takeoff and, at altitudes of less than 18,000 feet (flight level 180), thereafter from time-to-time to reflect changes in the local barometric pressure as the aircraft proceeds in flight—in order to provide the altimeter with an accurate reference against which to calculate changes in the aircraft altitude.
Prior art mechanical altimeters, typically implemented as discrete single-function instruments, include a pilot-graspable shaft-mounted knob that projects outwardly from the altimeter faceplate perimeter and which is selectively rotatable to enable manual setting, and resetting, of the local barometric pressure. Rotation of the knob changes the relative alignment of a numeric index scale with a pointer so that the pilot can, through such rotation, selectively adjust the scale to indicate that the current local pressure is, by way of illustration, 30.12 in. Hg. Because the numeric indications on the index scale are quite small and the consequences of an incorrect setting can be disastrous in certain situations, an unusual amount of pilot attention must be directed to the instrument when setting, or resetting, the altimeter adjustment. The potential for introducing inadvertent errors into the adjustment is understandably greater in flight, when the attention required to correctly effect the adjustment must come at the expense of the pilot's other responsibilities and workload in maintaining situational awareness and otherwise operating and controlling the aircraft.
Although these discrete mechanical altimeters are still commonly employed in the majority of smaller propeller-driven aircraft and, to a lesser extent, in small and larger jets and in other commercial aircraft, they are increasingly being replaced by digital flat panel displays (FPDs), and the associated control systems for providing the imaging data indicative of current aircraft altitude, on which the aircraft's current altitude is displayed for viewing and use by the pilot(s) and/or flight crew. In addition to current aircraft altitude the FPD will also typically continue to display the current local barometric pressure setting which has been manually input by the pilot or other user and on which the calculation of current aircraft altitude is based. That setting may be manually input, by way of illustrative example, through selective rotation of a rotatable knob or other user-manipulatable control that is expressly provided for that purpose, or via a keypad on which the numeric value of the local barometric (“baro”) pressure is entered, or by finger or stylus contact with a touch-sensitive pad or the surface of a touch-sensitive FPD. As with prior art mechanical altimeters, the current local pressure setting may, in any event, be periodically input or entered or adjusted with a high degree of accuracy, and thus, normally requires that the pilot devote special attention to assuring input of the correct setting, whether the aircraft is on the ground or in the course of flight.
The FPD on which the manually-input local barometric pressure setting is displayed, and on which the aircraft's current altitude is dynamically updated and displayed may be dedicated to providing that functionality alone, and can be implemented so that the FPD graphically depicts or simulates the appearance of a prior art mechanical altimeter with which all licensed pilots are familiar. Increasingly, however, the flight decks of large commercial passenger aircraft are provided with relatively large FPDs that display for the flight crew, in addition to aircraft altitude, a multiplicity of other types of aircraft status, flight, navigation and other aircraft and environmental data that is used in the operation and control of the aircraft. In either case, manual setting of the current local barometric pressure requires that special attention be directed and diverted to the FPD, on which the numeric pressure adjustment setting being entered or input is displayed among a crowded field of data and, in order to provide sufficient room to fit all of that data on the FPD, the barometric pressure setting is typically displayed in a relatively small format and/or numeric typesize, so that the pilot must devote unusual attention to the task of entering the desired setting in order to avoid inadvertent potentially-disastrous errors. This problem is especially apparent in multipurpose FPDs that concurrently display numerous different types of information and data to the aircraft pilot, thereby increasing the opportunity for a busy or task-overloaded pilot to inadvertently manipulate the wrong knob or control and/or to view the wrong onscreen data in entering the new setting, or in any event requiring that the pilot take more time and divert more attention to carefully effect the local barometric pressure setting adjustment than might otherwise be needed to do so.
As another example, engine and fuel information can be displayed on the FPD, whereby different measurements can be extracted from various sensors placed in the engine and fuel system and displayed on digital versions of traditional instruments. For example, when the aircraft is on the ground in idle state prior to takeoff, a graphically-depicted gauge instrument may show N1 RPM to be at 25%. During cruise phase, this may change to 90%. However, in some instances by way of illustration, reaching values more than 100% can result in significant failure and the pilot may want to take certain actions with respect to the engine before such levels are reached. However, because there may be many such gauges displayed, each showing slightly changing navigation, environmental, and other parameters on the heavily-populated FPD in small numeric indications, a pilot's attention may not be drawn in time to attend to such a situation. Alternatively, a pilot may want to know when a particular flight parameter value has reached, or is close to reaching, a particular target or reference value, such as a target RPM, altitude or a reference airspeed. Again, this problem is especially apparent in multipurpose FPDs, thereby increasing the opportunity for a busy or task-overloaded pilot to not notice or take appropriate action because of a failure to view the relevant onscreen data.